Image forming method combining heat and pressure to produce a color image
AssigneeSharp Kabushiki Kaisha
InventorsYoshiharu Tsujimoto, Kunio Ohashi, Yoshikazu Fujiwara, Hiromu Sasaki
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Abstract
A method for image formation comprising the steps of exposing a light-receiving sheet coated with a layer of microcapsules containing photopolymerization agent and colorless dye selectively to light so as to form a cured image thereon opposite in sense to the desired final image, laying an image-receiving sheet uniformly coated with a layer of a developing material for reacting with and coloring the colorless dye on the light-receiving sheet, heating the resulting sandwich configuration and pressing these sheets against each other thereby rupturing the uncured microcapsules to form a colored image.
Claims4
A method for color image formation comprising the sequential steps of:
- providing a light-receiving sheet coated with a layer of microcapsules dispersed in a binder resin, said microcapsules containing a photopolymerization agent and a colorless dye medium;
- selectively exposing said light-receiving sheet to actinic radiation thereby forming a cured image thereon opposite in sense to the final image desired leaving uncured microcapsules in an image configuration for the final image desired;
- contacting an image-receiving sheet coated with a developer layer comprising a binder and a developer material for reacting with and coloring said colorless dye in said microcapsules on said light-receiving sheet with said light-receiving sheet such that said developer layer is in surface contact with said exposed surface of said light-receiving sheet to form a sandwich configuration;
- preheating said sandwich configuration of said light-receiving sheet and said image-receiving sheet to a temperature such that said binders of said light-receiving sheet and said image-receiving sheet are softened thereby enhancing adhesion between said light-receiving and image-receiving sheets and lowering the viscosity of said medium within said microcapsules;
- applying pressure to said heated sandwich configuration of said light-receiving sheet and said image-receiving sheet by a pressure means thereby rupturing the uncured microcapsules on said light-receiving sheet, releasing said colorless dye to react with said developer material to form a colored image on said image-receiving sheet, said preheating taking place before said image-receiving sheet and said light-receiving sheet are pressured together;
- separating said light-receiving sheet from said image-receiving sheet following said image forming pressure step;
- and
- post-heating said image-receiving sheet by heat roller means to accelerate and complete image development at a temperature such that said binder will not offset to said heat roller means.
Dependencies are inferred from the claim text.